Seal construction



Aug. 31, 1954 s. VORECH SEAL CONSTRUCTION 2 Sheets-Sheet 1 OriginalFiled Dec. 29 1950 INVENTOR Sieplzen Voreclz ATTORNEYS Aug. 31, 1954 s.VORECH SEAL CONSTRUCTION 2 Sheets-Sheet 2 Original Filed Dec. 29, 1950 6la v I INVENTOR Si'ep/ww VOfClZ/,

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ATTORNEYS Patented Aug. 31, 1954 SEALv CONSTRUCTION Stephen Vorech,'Elyria, Ohio, assignor to Bendix- Westinghouse Automotive Air BrakeCompany, Elyria, Ohio, a corporation of Delaware Original app icationDecember 29, 1950, Serial No. 203,359. Divided and this applicationMarch 14, 1952, Serial No. 276,531

4 Claims. 1

This invention relates to fluid pressure actuated devices and moreparticularly to an actuator which may be well adapted for the actuationof automotive vehicle brakes equipped with a compressed air operatedbraking system.

One of the objects of the present invention is to provide a fluidpressure actuator of relatively small diameter which is highly effectiveinoperation and which may be readily incorporated in vehicle :air brakeinstallations to occupy a mumof space.

A further object is to provide in a fluid pressure actuator of the typehaving a pair of dished plates for providing a chamber and for clampingan actuating diaphragm therebetween, a novel construction for securingsuch plates and diaphragm together which avoids the use of holes in theperiphery of the diaphragm tor reception of the customary clampingscrews.

Another object of the invention resides in the use-of anovel clampingband or strap which may be quickly assembled with :the dished plates anddiaphragm to securely hold these parts position.

.Still another object is to provide .in a fluid pressure actuator of theforegoing character, .a novel arrangement .for sealing the actuatoragainst the entrance of dust, dirt and water, which might otherwiseseriously impair the efficiency .of the actuator, especially when in usein connection with vehicle braking installations.

A still further object is .to provide a leakproo'f actuator of smallsize and one which is so constructed as to have a substantially uniformoutput throughout its eiiective working ranges.

Other objects and novel features of the inventi'on will appear morefully hereinafter from the following detailed description when taken inconnection with the accompanying drawings. It is to be expresslyunderstood, however, that "the drawings are utilized for purposes ofillustration only and are not dei'sgned as a definition of the limits ofthe invention, reference being had for this purpose, to the appendedclaims.

In the drawings wherein similar reference characters refer to similar"parts throughout the several views:

Fig. 1 is .an axial sectional View of a fluid pressure actuatorconstructed in accordance with the principles of the present invention;

Fig. 2 is an end view of the actuator and illustrates a portion of theclamping strap or band in section;

Fig. 3 is a :planviewof the clamping strap;

Fig. 4 is a perspective view of the shell tor housing the elements ofthe push rod seal;

Fig. '5 is another perspective view of the shell of Fig. 4;

Figs. 6, 7, 8 and 9 are partial views in section of modified forms ofclamping devices for the dished plates and diaphragm, and

Fig. 10 is a partial viewinsecti-on of a modified form of breather orvent for the actuator.

Referring more particularly to Figs. 1 and 2, the novel fluid pressureactuator 2 of the present invention is illustrated therein as beingformed from a pressure'plate l and a non-pressure plate 6. these platesbeing dished, as shown, and being clamped together and to the peripheralportion 8 of a flexible diaphragm III, of reinforced rubber composition,the construction being such that a pressure chamber l2 and anatmospheric chamber M are formed on opposite sides of the diaphragm It.A pair of studs H3 and 18 together with nuts H and F9 are provided formounting the actuator 2 on a convenient mounting bracket (not shown) anda port 20 is formed in the pressure plate 4 for admitting compressedair-or other fluid pressure to the pressure chamber 12 in order to movethe diaphragm 10 to the right, as viewed in Fig. 1. Such movement of thediaphragm it causes a corresponding movementof a plate '22 having a pushrod "24 rigidly connected therewith, the latter extending outwardlythrough an enlarged opening 26, in the plate 5, and having its outer endthreaded at 2 8" order to adapt the push rod 2 8 for connection with thepart to be actuated, such as a slack adjuster in compressed air brakeinstallations for automotive vehicles. A spring so is confined betweenthe end wall of the plate 15 and the plate 22 .to normally maintain thelatter in engagement at :all times, with the diaphragm lit, and toreturn the latter to the position illustrated when fluid "pressure isexhausted from the pressure (chamber 12, while the enlarged opening 26allows :a limited amount of lateral movement of the push rod 2 duringoperation of the actuator.

:One of the features of the present invention resides in the formationof the pressure plate 4 so that its surface .32, against which thediaphragm it lies when the actuator 2 is inoperative, is positioned .ata relatively slight angle with respect to a horizontal plane. Due tothis construction, as the diaphragm H3 is moved to the right, during itsworking stroke, the effective .area thereof subjected to the pressurefluid will not materially increase, and the actuator output will besubstantially uniform throughout its effective working range. Inaddition, this construction contributes .to the reduction in diameter ofthe unit.

Novel means are provided for securing the plates 4 and 6 and thediaphragm I together, and in the form shown in Figs. 1, 2 and 3, suchmeans enables the aforementioned parts to be quickly and effectivelyassembled. More particularly, the peripheral or marginal portion 6 ofthe: diaphragm I6 is provided with an enlarged peripheral bead 34 sothat when the plates 4 and 6 are assembled, the diaphragm will besecurely held at its marginal edge. The novel securingmeans, in the formshown in Figs. 1, 2 and is constituted by a channel-shaped strap or band36 which is adapted to encircle the plates 4 and 6. Opposite ends of thestrap 36- are respectively provided with lateral extensions 38, 48 and42, 44 which are suitably apertured for reception of bolts and nuts 46and 4B in order that the strap 36 may be tightened. When the oppositeends of the strap 36 are brought toward each other, through tighteningof the bolts and nuts 46 and 48, the channel-shaped strap 36 will movethe plates 4 and 6 toward each other with an appreciabl force in orderto secure these parts firmly together with the diaphragm bead 34interposed therebetween. This squeezing or clamping action is achievedby coaction between the tapered Walls 58 and 52 of the respective plates4 and 6, and the tapered walls 54 and 56 of the strap 36-. Moreparticularly, the walls 56 and 52 constitute a pair of annularconvergent shoulders which cooperate with the annular divergentshoulders 54 and 56 formed by the tapered Walls 54 and 56 of the strap36. Thus, the use of the strap 36 securely clamps the above partstogether and avoids the necessity of drilling bolt holes in theperipheral portions of the plates 4 and 6 and the diaphragm II] in orderthat these parts may be assembled with bolts. Hence, the construction ofthe invention further contributes to the reduction in the diameter ofthe actuator as well as providing an arrangement enabling the parts tobe quickly assembled.

In order to vent the chamber I4 to the atmosphere, a novel breatherconnection or vent 58 is provided. As shown, such vent 58 is formed inthe stud I8 and is constituted by a longitudinal bore 60 whichcommunicates adjacent its outer end with a plurality of lateral bores62. The stud I3 is of sufiicient length so that the lateral bores 62will not be closed by the nut I! when the actuator 2 is mounted inoperative position. From this construction, it will be readily seen thatthe bores 60 and 62 form a labyrinth for the passage of air whileeffectively preventing the entrance of water and dirt into the actuator.It will be understood, of course, that the labyrinth vent constructionmay be formed separately from the stud I8, if desired.

A further feature of the invention includes the use of a novel sealconstruction which is associated with the push rod 24 and with theopening 26 in order to prevent the entrance of water, dirt and otherforeign matter into the actuator during operation of the latter. Asshown, Figs. 1, 4 and 5, such seal construction comprises a seal 64which includes alternate discs of oil and wear resisting rubbercomposition 66 and 68 and felt I0 and I2, the latter being saturatedwith lubricant, and all of the discs being confined within a shell 74.Preferably, the discs 66, 68, I8 and I2 are assembled within the shell14 alon with a metal disc I6, as shown in Fig. l, and the shell I4 ispunched inwardly at a plurality of points 80 around the peripherythereof in order to securely maintain the parts in position in the shelland to provide a unitary assembly. Also, the shell 14 is cut out toprovide a plurality of laterally extending ears or lugs 82 which form aseat for one end of a spring 84, the opposite end of the spring seatingagainst the plate 22 and thus serving to maintain the seal 64 in theposition illustrated in Fig. 1. In addition to the foregoing, the shell14 is formed to provide a short axial extension 86 for slidablyreceiving the push rod 24, it being pointed out that the metal disc I6also has a sliding fit with respect to the push rod 24. In this manner,any side thrust of the push rod 24 is taken through the metal disc I6and the extension 86, thus relieving side thrusts from the sealing discs66, 68, I8 and I2 and increasing the wearing qualities of the latter.

As shown in Figs. 1 and 5, the shell 14 is also formed to provide anannular bead or projection 88 which bears against the end portion 90 ofthe plate 6 when the seal 64 is assembled in operative position. Withsuch an arrangement, an annular line contact is obtained between theshell I4 and the casing end portion 90 which forms an effective seal forthe chamber I4 and also minimizes the frictional drag between the shelland end portion during lateral movement of the push rod 24 and seal 84with respect to the enlarged opening 26.

While Figs. 1, 2 and 3 illustrate the preferred manner of securing theplates 4 and 6 and the diaphragm I8 together to form the novel actuatorof the invention, it will be understood that various modifiedconstructions may be utilized which also avoid the use of a series ofperipheral holes and the clamping bolts heretofore utilized. Forexample, in Fig. 6, the clamping ring 92 may be continuous, instead ofsplit as in Fig. 1, and may be crimped over the marginal edges of theplates 4 and 6. In Fig. '7, the clamping ring 94 may also be continuousand formed to threadedly engage one of the plates 6. Figs. 8 and 9illustrate further modifications of the use of a continuous clampingband 66 wherein a split locking ring 88 is utilized to lock the parts inassembled condition. Fig. 9 also illustrates a modified arrangement forclamping the bead 34 of the diaphragm I0 wherein the bead is directedaxially instead of radially as in Fig. 1.

In Fig. 10, a modified type of push rod seal is illustrated andcomprises an axially extending sleeve I00 which is secured to the endportion 90 and which is provided with an enlarged opening I82 throughwhich the push rod 24 extends. A rubber boot I84 is tightly fitted onthe rod 24 and when the actuator is in a released position, the outeredge I66 of the boot contacts the end portion 88 to seal the interior ofthe actuator. During operation of the actuator, the boot I04 will becarried with the rod 24 during movement of the latter and thus thearrangement performs the function of the breather or vent 58 of Fig. 1.Until the edge I06 contacts the end portion 90, air may pass freelythrough the opening I62. It will be noted, however, that during suchpassage of air, the direction of fiow is axial through the labyrinthpassage for air is provided and during the release period, a tight sealis secured.

In operation of the form of the invention illustrated in Figs. 1, 2 and3, it will be seen that after the seal 64 has been assembled and fittedon the push rod 24, it is only necessary to place the springs 30 and 84between the plates 4 and 6 and clamp the latter and the annulardiaphragm bead 39 together to obtain the actuator assembly 2 as shown inFig. 1. With the actuator mounted on any suitable bracket, by means ofthe studs l6 and I8, the device may be charged with air pressure inorder to move the diaphragm l0 and parts associated therewith to applythe vehicle brake or other part to be actuated. During application andrelease movement of the push rod 24 the seal 64 will be effective toprevent the entrance of water and dirt into the chamber 14, it beingpointed out that the enlarged opening 26 enables lateral movement of therod 24 to take place, while the annular line contact between the bead B8of the shell 14 and the end portion 99 of the shell 6 minimizes thefriction between these parts while insuring an effective seal. Inaddition to the above, the construction of the bores 60 and 62 of thebreather 58 is such as to provide a labyrinth passage for air passinginto and out of the actuator during movement of the diaphragm In inopposite directions, in order to further protect the actuator from dirtand water while insuring the free passage of air through the breather inopposite directions.

This application is a division of my application Serial Number 203,359filed December 29, 1950, for Fluid Pressure Actuator.

While several embodiments of the invention have been shown and describedherein, it will be well understood by those skilled in the art that theinvention is not limited to these but may be embodied in other formswithout departing from the spirit of the invention. Reference willtherefore be had to the appended claims for a definition of the limitsof the invention.

What is claimed is:

1. In a fluid pressure actuator of the type having a push rod axiallymovable in opposite directions and wherein said rod extends through anenlarged opening in one of the walls of the actuator to allow lateralmovement of the rod during said axial movements, the improvement whichcomprises a water and dirt excluding seal surrounding the push rod andincluding a shell having a cylindrical portion and an end wall, thelatter being apertured and provided with an axially extending sleeveslidably engaging said rod, 2. series of annular sealing members withinthe shell, an annular metal member slidably engaging the push rod andcontacting said series of sealing members, the cylindrical portion ofthe shell being punched inwardly to confine all of said annular memberswithin the shell, and being also formed with a plurality of integralears extending laterally of the cylindrical portion, and the end wall ofthe shell having an annular bead extending outwardly thereof to contactsaid one wall of the actuator around said enlarged opening.

2. In a fluid pressure actuator of the type having a non-pressure plateprovided with an end wall having an opening therein, an actuating rod ofsmaller diameter than said opening and reciprocable and laterallymovable in said opening, and an expansible spring surrounding said rod,the improvement comprising a packing seal assembly surrounding said rod,including a cupshaped shell having an end wall provided with an axialextension engaging the periphery of said rod and provided also with anannular bead concentric with the extension, said shell also having asecond end wall, a plurality of annular sealing discs surrounding saidrod and positioned within the shell and confined between the end wallsthereof, and means carried by the shell and interposed between saidspring and the end Wall of said plate so that the force of said springmaintains said annular head in contact with the end wall of said plate.

3. In a fluid pressure actuator of the type having an actuating rodaxially movable in opposite directions and wherein said rod extendsthrough an enlarged opening in one of the walls of the actuator to allowlateral movement of the rod during axial movements thereof, theimprovement which comprises a packing seal assembly surrounding said rodand including a shell having a cylindrical portion and an end wall, thelatter provided with an axial extension projecting outwardly from saidend wall and slidably engaging said rod, a plurality of annular sealingdiscs within the shell, an annular metal disc slidably engaging the rodand forming a second end wall of said shell, means for compressing saidsealing discs together and between the end walls of said shell, and acontinuous, annular projection extending outwardly of the plane of thefirst named end wall and in the same direction as said axial extension,said annular projection having a diameter which is greater than that ofsaid opening to contact said one wall of the actuator around saidenlarged opening.

4. The improvement set forth in claim 3 which includes in addition, aplurality of ears struck out of said cylindrical portion and extendinglaterally thereof.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,554,659 Rudolph Sept. 22, 1925 1,911,670 Black May 30, 19332,608,422 Allinquant Aug. 26, 1952 FOREIGN PATENTS Number Country Date598,530 France Sept. 29, 1925

